The invention relates to a heating/air-conditioning device of reduced size for a motor vehicle.
Heating/air conditioning devices are known that are suitable for being housed in a motor vehicle instrument panel and typically comprise a blower sending a flow of air through an evaporator and through a heating radiator. The airflow is then diffused into the passenger compartment of the vehicle by air-distribution means.
In a device of this type, the blower is fed either with external air taken from outside the passenger compartment of the vehicle, or with recirculated air taken from within the passenger compartment. The blower sends a flow of air through the evaporator, which is linked to a conventional air-conditioning circuit, and possibly through the heating radiator which is usually traversed by a hot fluid, namely the liquid for cooling the engine of the vehicle. The airflow thus cooled and/or heated is distributed, by virtue of the air of distribution means, between various nozzles opening into the passenger compartment.
Moreover, such a device usually comprises an air filter arranged on the path of the airflow so as to retain the impurities transported by the air, this air filter usually being arranged between the blower and the evaporator.
It has recently been proposed to group together the elements constituting the device into a space of generally rectangular shape within the instrument panel so as to obtain a saving in space and to allow standardization of manufacture.
However, this solution dictates a horizontal position for the evaporator, as well as a long circulation path for the airflow, which gives rise to losses of pressure and thermal losses.
A device of this type is described, for example, in the document EP 0 788 907.
An object of the invention is to at least partly mitigate the above-mentioned drawbacks
A heating/air-conditioning device suitable for being housed in an instrument panel of a motor vehicle and comprising a blower sending a flow of air through an evaporator and through a heating radiator, the airflow then being diffused into the passenger compartment of the vehicle by air-distribution means, The principal surface of the evaporator extends in a first principal plane and the principal surface of the heating radiator extends in a second principal plane. The evaporator is traversed by a flow of air along a first direction substantially perpendicular to the first principal plane. The airflow is then diverted by first deflector means so as to orient it along a second direction substantially perpendicular to the second principal plane, such that at least a part of the airflow passes through the heating radiator, this part then being diverted by second deflector means so as to orient it along a direction substantially parallel to the second principal plane.
By virtue of this structure, the airflow undergoes an overall right-angled diversion between passing over the evaporator and passing over the radiator. As the airflow always passes over the radiator, it is not necessary to provide an air mixing flap as usually employed to mix a cold airflow and a hot airflow, which flow gives rise to the large size of conventional devices.
The outlet from the heating radiator preferably communicates with an outlet chamber, the latter communicating directly with the air-distribution means via a distribution flap.
This direct communication thus avoids the use of the mixing flap which is usually arranged between the heating radiator and the air-distribution means.
The heating radiator is advantageously a heat exchanger of the liquid/air type suitable for being traversed by a hot fluid and fitted with a cock for adjusting the throughput of the hot fluid.
In one embodiment of the invention, the device further comprises a take-off duct which communicates, on the one side, with the first deflector means and, on the other side, with the outlet chamber. The take-off duct is under the control of an adjusting flap, in such a way that the outlet chamber is fed with a flow of air originating from the heating radiator and, if appropriate, with a flow of air originating from the evaporator.
The first deflector means advantageously comprises an angled channel.
The second deflector means advantageously comprises a partition of a casing.
The device of the invention may further comprise an electric booster radiator arranged downstream of the heating radiator in such a way that the airflow passes successively through the heating radiator and the electric booster radiator.
In one advantageous embodiment, the air-distribution means comprises at least one ventilation duct which forms a connection between the outlet chamber and at least one ventilation nozzle provided in the instrument panel.
The air-distribution means preferably further comprises at least one de-icing duct which forms a connection between the outlet chamber and at least one de-icing/de-misting nozzle.
In one advantageous embodiment, the air-distribution means comprises a lateral de-icing duct which is delimited at least in part by a hollow beam serving as reinforcement for the instrument panel and forming a connection between the outlet chamber and the lateral de-icing nozzles.
Also advantageously, the air-distribution means comprises an upper de-icing duct which communicates with the outlet chamber via a connecting duct and which communicates with nozzles for de-icing/de-misting the windscreen.
According to another advantageous characteristic, the air-distribution means comprises a lower ventilation duct which forms a connection between the outlet chamber and at least one ventilation nozzle opening out low down in the passenger compartment, in the region of the passengers"" feet.
It is advantageous for the lower ventilation duct to communicate with the outlet chamber by means of the connecting duct defined above, so that this connecting duct communicates both with the upper de-icing duct and with the lower ventilation duct.
An adjusting flap is then advantageously provided at the intersection of the connecting duct, the upper de-icing duct and the lower ventilation duct in order selectively to direct a flow of air to the upper de-icing duct and/or the lower ventilation duct.
According to another characteristic of the invention, the device comprises an air-distribution flap arranged at one end of the outlet chamber and an intermediate position for the air-distribution flap is provided, in which the outlet chamber communicates with the upper de-icing duct via the connecting duct and in which the lateral de-icing duct is obstructed.
According to yet another characteristic of the invention, the upper de-icing duct and the lower ventilation duct both extend along the bulkhead which separates the engine compartment from the passenger compartment of the vehicle.
The invention also provides for one wall of the lower ventilation duct and/or one wall of the upper de-icing duct to comprise soundproofing cladding of the bulkhead which separates the engine compartment from the passenger compartment of the vehicle.
In this case, it is advantageous for the wall of the lower ventilation duct and the wall of the upper de-icing duct to be a single wall comprising the soundproofing cladding of the bulkhead.
The connecting duct may further comprise an electric booster radiator for heating the airflow discharged through the upper de-icing duct and/or through the lower ventilation duct.
Advantageously, the device includes independent heating controls for setting the heating radiator and the electric booster radiator.
According to another characteristic of the invention, the blower, the evaporator, the heating radiator and at least a part of the distribution means are included in a casing suitable for being integrated into the instrument panel.
Advantageously, this casing is intended to be placed on the same side as the driving position and above the steering column.
According to yet another characteristic of the invention, in a principal cross-section, the casing exhibits a trapezoidal shape which is elongate along a longitudinal axis substantially parallel to the steering column of the vehicle, and the ratio between the dimension of the casing along this longitudinal axis and the dimension of the casing along an axis perpendicular to this longitudinal axis is substantially greater than or equal to 1.3.
Preferably, the ratio between the dimension of the casing along the longitudinal axis and the dimension of the casing along the perpendicular axis is substantially equal to 1.6.